Evaluation of the forest damage by typhoon using remote sensing technique

The forest damage (fallen trees) by a typhoon or a strong wind is frequently generated in recent years. For example, typhoon SONGDA (2004.09) brought about destructive strong winds to almost western half of Hokkaido. According to a temporary report issued by Japan Meteorological Agency, in Sapporo, 50.2 m/s was recorded as a maximum instantaneous wind speed in the history of observation. This typhoon also caused serious damage to the forest of Hokkaido. ASTER (advanced spaceborne thermal emission and reflection radiometer) aboard NASA´s satellite Terra is a high resolution multispectral radiometer of 14 bands. The spatial resolution is 15 m in visible and near infrared, 30 m in short wave infrared and 90 m in thermal infrared spectra respectively. Data from ASTER were used to produce the along of fallen trees extraction for the south western coastal area of Hokkaido. We evaluated the damage of forestry based on the spectrum characteristics of fallen trees. As a result the extraction of almost all fallen trees data has been succeeded.